Method for producing stable alkali polysulphides



Patented Apr. 20, 1937 2,077,85

UNITED STATES PATENT OFFIQE METHOD FOR PRODUCING STABLE ALKALI- POLYSULPHIDES Otto Rohm, Darmstadt, Germany No Drawing. Application March 3, 1936, Serial No. 66,943. In Germany April 1, 1935 6 Claims. (Cl. 23-138) The invention relates to stabilized alkali polyuntil the latter enters into solution. 10 parts of sulphides and to methods of producing the same. potassium thiocyanate are then incorporated Alkali polysulphides are much used technically, with the reaction mixture.

one of the uses being for the extermination of Example 2.-100 parts of an alkali polysulphide pests. However, owing to their poor keeping prepared as for Example 1, or otherwise, are

qualities, the use of alkali polysulphides in either mixed with 3 parts of sodium thiocyanate and the i solid or dissolved form is quite limited. reaction mixture mixed with 500-900 parts of It has already been proposed to stabilize alkali soap, e. g. powdered soap or rosin soap, in a polysulphide solutions by adding substances kneading machine.

thereto which are soluble therein, such, for ex- By using thiocyanogen salts within the mean- 10 ample, as various kinds of sugars, alcohols such ing of the invention, it is readily possible to proas glycerin, etc. Of these addition agents, as far duce commercial dry powdered products. A very .as applicant is aware, only glycerin has attained mple p oc du can be used. y drying the :technical significance. The other addition agents mixture of p ys p d and potassium th oso far recommended have only a very deficient cyanate in vacuo.

stabilizing effect. Example 3.65 parts of crystallized sodium It has been found that alkali polysulphides may sulphide and 8. Parts of Sodium thioeyahete r be stabilized in an exceptional manner by means melted toge her and the fusion mass boiled with of thiocyanogen compounds. All soluble thio- 26.5 pa ts of p Twice the q y 0f cyanogen salts are suitable except ammonium soap is introduced into the finished polysulphide. 20 thiocyanate, which, as is well known, becomes Such a dry p t ay be dissolved n 30 to 50 altered by alkalies. times as much water and used advantageously The polysulphides may be produced by the for sprayin pest e d p s. usual methods, e. g. by fusing sulphur with sul- I claim: 5 phides or by boiling sulphur in sulphide solutions. S a ew Composition of matter, an alkali The thiocyanogen salt may be incorporated with polysulphide Stabilized y ure With an the alkali polysulphide or with a solution thereof. a i m a t oya ate.

The alkali polysulphide may be employed as 2. As a new composition of matter, an alkali such or in combination with other materials such polysulphide Stabilized y tu 'e With Sodium as soap. For example, mixtures may be made thiocyanate. 30 of alkali polysulphides with commercial powdered 3- As a new c mp sition f m tter, an alkali soaps, or even rosin soaps, and the stabilizing subp y e Stabilized y admixture With P stance or thiocyanogen salts incorporated either slum thiocyanate. prior to or during the preparation of such mix- A method of producing Stable alkali p ytures. In this way dry powders may be produced sulphides which comprises melting crystalline 35 which are easy to pack, ship, and measure out sodium sulphide in its water of crystallization and for use, boiling the same with powdered sulphur until The applicability of thiocyanogen salts as the latter enters solution, then incorporating stabilizing agents for alkali polysulphides and potassium thiocyanate with the reaction mixture.

their solutions could not have been deduced from 5. A process of stabilizing alkali polysulphides, 0

the hitherto proposed stabilizing agents. The use which comprises mixing therewith od u thioof thiocyanogen salts, furthermore, presents the cyanate and kneading the m Xtul'e. advantage that these by themselves possess A D of producing Stabilized alkali P ygermicidal properties. This renders it possible to su ph Which Comprises melting ther secure acombination efiect. crystallized sodium sulphide and sodium thio- 45 Example 1.--64 parts of crystalline sodium sulya a a boiling the fusiOn ass With sulphur phide are melted in its water of crystallization until a reaction, takes P and boiled with 33 parts of powdered sulphur OTTO ROHM. 

